[en] Published in summary form only

[en] In this work a 2³ factorial design was carried out aiming the multivariate optimization of Instrumental Neutron Activation Analysis (INAA) for mass fraction determination of Co, Cr, Fe, Rb, Sc, Se and Zn in biological samples and Co, Cr, Fe, Sc and Zn in geological samples. The factors investigated in this study were sample decay time, sample distance to detector and sample measurement time. The optimal condition for each method was outlined according to the main effect and interactions results. It was observed that sample decay time is the most important factor for the INAA optimization in the different methods. (author)

No abstract available

No abstract available

[en] Instrumental neutron activation analysis was used to evaluate the between bottle homogeneity and the minimum sample intake of a bovine kidney candidate reference material. The mass fractions of ten inorganic constituents were determined, obtaining satisfactory homogeneity results for all of them. Statistical analysis of the results was performed using a one way analysis of variance and multivariate techniques were applied as complementary techniques, confirming the usefulness of these techniques for homogeneity assessment. (author)

[en] The production of certified reference materials in Brazil, and the consequent availability to national end users, is an important task for the enhancement of Metrology in Chemistry status in the country, as these materials are used for method validation, equipment calibration and for establishing metrological traceability links. In this study, Instrumental Neutron Activation Analysis (INAA) was applied to the determination of bromine, chlorine, magnesium, manganese, potassium and vanadium in a mussel reference material produced at IPEN-CNEN/SP. For the determination of these elements via the comparative INAA method, the respective analytical radionuclides, ⁸⁰Br, ³⁸Cl, ²⁷Mg, ⁵⁶Mn, ⁴²K and ⁵²V, are short lived and then, short irradiations are used. Six subsamples from two bottles of the Perna perna mussel reference material were analyzed. Each subsample was simultaneously irradiated with elemental standards for 10 s at the IEA-R1 research nuclear reactor through a pneumatic transfer system. After suitable decay periods, gamma radioactivity measurements were carried out, using a hyperpure germanium detector. The accuracy of the method was checked by using the NIST SRM 1566b-'Oyster Tissue' certified reference material. The comparison of the results obtained in this study to the robust mean of the interlaboratorial collaborative trial used for the characterization of the mussel reference material was performed via z-score tests. The comparison showed that the short irradiation INAA method is suitable for the characterization of new reference materials. (author)

[en] The element content as well as the particle size distribution of a new mussel candidate reference material was investigated. Instrumental Neutron Activation Analysis was applied for the determination of 15 elements in seven fractions of the material. Three vials of the candidate reference material and three coarser fractions were analyzed by Laser Diffraction Particle Analysis to determine the particle size distribution. Differences on element content were detected for fractions with different particle size distributions, indicating the importance of particle size control for biological reference materials. (author)

[en] Toxic elements in contact with the human body cause numerous health problems. The contamination occurs mostly by food consumption, such as the ingestion of fish contaminated with high concentrations of As, Cd, Hg or Pb among other elements. Many fishermen and their family members end up exposing themselves to different toxic elements due to fish-based diet as the main protein nutrient because they are unaware of the health risks associated with the consumption of fish from contaminated waters. In the present study, quantification of the toxic or potentially toxic elements As, Br, Cs, Cr, Co, Fe, K, Na, Sc, Se and Zn in samples of fish of the genus Astyanax (known by the common name of lambari). The fish was collected at Billings Reservoir by fishermen from the Riacho Grande District - (São Bernardo do Campo city, São Paulo State, Brazil) is presented. The lambari fish had great relevance in this study because it is consumed as a snack, in which the subject feeds on the whole organism of the fish, having a greater risk of direct contact with toxic elements through ingestion. Elements were determined by Instrumental Neutron Activation Analysis (INAA). This study is important in establishing an updated spatiotemporal vision of the contamination by various elements of interest in the region. Additionally, it contributes to the food safety assurance, regarding inorganic contaminants referred by the Brazilian Health Regulatory Agency (ANVISA). (author)

[en] Homogeneity study is one of the steps in reference material, RM, characterization. Due to its inherent characteristics, Instrumental Neutron Activation Analysis, INAA, is an analytical technique of choice for homogeneity testing. An interesting possibility is the use of complementary gamma ray photopeaks to confirm INAA homogeneity test results. In this study, the use of the complementary gamma ray photopeaks of ¹¹⁰mAg, ⁸²Br, ⁶⁰Co, ¹³⁴Cs, ¹⁵²Eu, ⁵⁹Fe, ¹⁴⁰La, ²³³Pa (for Th determination), ⁴⁶Sc and ⁷⁵Se radionuclides was investigated in the between bottle homogeneity study of a mussel candidate RM under preparation at IPEN-CNEN/SP. Although some photopeaks led to biased element content results, the use of complementary gamma ray photopeaks proved to be helpful in supporting homogeneity study conclusions for the new RM under characterization. (author)

[en] Instrumental neutron activation analysis was used at a 2-month long isochronous short term stability test performed on a Perna perna mussel candidate reference material. The assessment of the analysis of variance test, as well as, the normalized results to the control temperature showed no systematic changes in the concentration of Ag, As, Br, Co, Cr, Cs, Fe, Eu, La, Na, Rb, Se, Sc, Th and Zn during the test period. The result showed that the candidate reference material may be transported under normal transport conditions without significant changes in composition for the determined elements. (author)